Extech ex400 series digital multimeter dmm extech ex410 the extech ex410 digital multimeter is a robust and reliable multimeter with an affordable price tag the meter has switchable backlighting to conserve battery life and manual range selection it measures acdc voltage and current plus resistance diode test continuity and temperature using a built in type k thermocouple it features very low current capability measuring down to 01956a dc for additional safety it has input fus